Pipe coupling



FIG. 1 is an isometric view for our design for a pipe coupling;

FIG. 2 is a front view thereof;

FIG. 3 is a left side view thereof, the right side view being a mirror image thereof;

FIG. 4 is a top view thereof; and,

FIG. 5 is a bottom view thereof.

The broken lines represent portions of the pipe coupling that form no part of the claimed design. The pattern of circles on the top and bottom of the pipe coupling are in broken line and form no part of the claimed design. 

CLAIM We claim the ornamental design for a pipe coupling, as shown and described. 